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HBV is efficiently and selectively sequestered from the circulation by the liver. Since
hepatocytes bind HBV inefficiently, we hypothesized that non-parenchymal liver cells might
take up HBV and mediate hepatocyte targeting by transcytosis.
To study this, we developed a model in which human liver tissue is ex vivo perfused via
branches of the portal vein in the presence of human serum. The intact human liver
microarchitecture allowed us to investigate HBV liver cell interactions occurring in vivo. When
a fraction of fluorescence labelled viral particles (VP) was used for 45 minutes perfusion,
accumulation of VP was only observed in CD68 positive Kupffer cells but not in hepatocytes.
This was also the case for unlabelled VP as determined by immunofluorescence staining with
anti-HBs antibodies. Ultrastructural analysis by electron microscopy showed uptake of virions
into endosomes in close association to triglyceride rich lipoproteins (TRL).
To reach its host cell, however, the virus needs to be released from Kupffer cells again. When
human liver tissue was perfused for further 15 hours with VP negative medium, hepatocytes
became positive only when Kupffer cells became negative.
In line with HBV recycling in vivo, VP escaped lysosomal compartments and concentrated in
FITC-transferrin positive recycling endosomes in cultured human Kupffer cells. As shown for
retroendocytosis of TRL derived cholesterol, VP (coincubated with human serum) colocalized
with ApoA1 and ApoE, VP containing compartments were targeted by fluorescence labelled
HDL, and resecretion of fluorescence labelled as well as unlabelled VP was induced by HDL
or human serum as determined by flow cytometry, quantitative RT-PCR and ELISA. Our
hypothesis that HBV re-secretion out of Kupffer cells is associated with macrophage
cholesterol efflux in vivo is emphasized by our observation that VP migrate towards and into
hepatocytes along neutral lipids derived from Kupffer cells in ex vivo perfused human liver
tissue.

so if we lower cholesterol efflux from macrophages we reduce hbv virions reaching hepatocytes?

what do you think?it is too complicated for me since i dont know how cholesterol is managed by human body

anyway these are the results of cholesterol lowering by natural statins monacoli k (red yeast rice) 3mg daily and glutathione liposoms 9000mg daily which are reported in many studies as antiviral effect impairing hbsag secretion and infectivity of virions

Hepatitis B virus infection is dependent on cholesterol in the viral envelope.
Bremer CM, Bung C, Kott N, Hardt M, Glebe D.
Source
Institute of Medical Virology, Justus Liebig University, Frankfurter Str. 107, 35392, Giessen, Germany.
Abstract
The viral and cellular determinants leading to binding and entry of hepatitis B virus (HBV) are still not fully understood. We found that HBV infection of primary hepatocyte cultures is dependent on the presence of cholesterol in the viral envelope. Extraction of cholesterol from HBV purified from plasma of HBV-infected patients with methyl-beta-cyclodextrin (MbetaCD) leads to a strongly reduced level of infection. The cholesterol-depleted virions showed higher buoyant density (1.23 versus 1.17 g ml(-1)), a smaller diameter (39 versus 48 nm), but maintained particle integrity, antigenicity and ability to bind to hepatocytes. Although addition of exogenous cholesterol and cholesterol analogues restored the physical appearance of cholesterol-depleted virions, infectivity was only regained by cholesterol add-back. Infectivity of HBV produced from cell culture in the presence of inhibitors of cholesterol-synthesis is severely impaired. Interestingly, cholesterol extraction from cellular membranes, incubation with filipin and the protein tyrosine kinase inhibitor genistein showed no effect on HBV infection, excluding a role of lipid rafts for the infection process of HBV. In summary, presence of cholesterol within the viral envelope is not important for viral binding, but indispensable for the entry process of HBV and might be important for a later step in viral uptake, e.g. fusion in a yet unknown compartment.

FIG. 9. Model for cholesterol dependence of DHBV entry into hepatocytes. DHBV infection initiates with attachment of viral particles to
binding sites preferentially located in detergent-soluble domains of the plasma membrane. Following attachment, viral particles are internalized
by endocytosis. Endosomal exit of incoming viral particles strongly depends on the cholesterol content of the virus membrane. Cholesterol
depletion from the virus membrane results in their endosomal entrapment and presumably proteolytic clearance leading to abrogation of infection

according to our data, depletion of cholesterol from host membraneto our data, depletion of cholesterol from host membrane
does not interfere with the permissiveness of hepatocytes for
DHBV. The ﬁnding that DHBV preferentially binds to DSMs
on the plasma membrane further strengthens this notion.
Thus, cholesterol dependence provides a novel example for
both conservation of and variation in host factor requirements
by different viruses.
The amount of viral L protein and its dual topology were not
signiﬁcantly impaired in cholesterol-depleted particles compared to control ones. Thus, it appears that hepadnaviral envelope proteins alone are necessary, but insufﬁcient, to induce
membrane fusion and depend on certain lipids, in particular
cholesterol, to exert their function. Consistent with this are the
changes in the ultrastructural appearance of the DHBV envelope upon cholesterol depletion. Loss of infectivity of DHBV
and HBV virions after cholesterol depletion was dose dependent with a 50% effective concentration of about 2.5 mM,
indicating that a certain cholesterol concentration is needed
for the functionality of the virus membrane. Rearrangements
within the entire envelope and/or particular microdomains
necessary for infection appear to be increasingly restricted by
lowering the membrane cholesterol content.
Overall, our data clearly demonstrate that virion-associated
cholesterol is required for structural integrity and infectivity of
hepatitis B viruses. As depicted in the model in Fig. 9, cholesterol seems to be essential for the membrane-membrane/protein interaction during the endosomal stage of virus entry. If
this interaction is disturbed, viral particles are presumably not
released from the endosome and degraded. However, the
mechanism(s) by which cholesterol controls endosomal escape
of the incoming virions is currently not clear. Cholesteroldependent rearrangements within the virus envelope may be required for fusion of the virus envelope with the endosomal
membrane. Mutually not exclusive, cholesterol may be required for the release of capsids out of the endosomal compartment subsequent to fusion pore formation.

statistical data showed that higher hdl has an antiviral effect on hbv

this last study clears how depleted cholesterol disturbes viral fusion before hbsag and cccdna formation, fig 9, so with my effort of lowering cholesterol we should see a weaker virus although i have no idea how long it takes to see an impact on hbsag and cccdna values.i think this will be easier to see within an active infection with continuous hbvdna, cccdna, hbsag formation

Antiviral Res. 1999 Jul;42(3):211-8.
Lipoproteins account for part of the broad non-specific antiviral activity of human serum.
Singh IP, Chopra AK, Coppenhaver DH, Ananatharamaiah GM, Baron S.
Source
Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston 77555-1019, USA.
Abstract
Several antiviral substances have been detected in human serum but few have been shown to possess broad antiviral activity. These broadly active antiviral molecules could be of significance as innate defense mechanisms. We have previously identified and characterized a broadly antiviral glycoprotein, UTI3, which accounts for 50 antiviral units/ml of human and mammalian sera. In addition there are reports of antiviral activity of human serum apolipoprotein A-1 (apo A-1), an important constituent of high density lipoprotein (HDL), against human immunodeficiency virus (HIV) and herpesvirus. Therefore we investigated (1) whether HDL is broadly antiviral, (2) how much of the broad antiviral activity of serum is due to HDL, and (3) the mechanism(s) of HDL's antiviral action. In this paper we report that (1) HDL does have broad antiviral activity, (2) HDL accounts for a modest but significant portion of the antiviral activity of serum, and (3) HDL acts by preventing virus penetration. Overall, HDL may be one of the broadly antiviral defences in the bloodstream.

".... Only four broad-spectrum viral inhibitors have
been reported in human sera. IFN and TNF occur
in response to infections, inflammation and cancer
[16±19]. The others are constitutive, i.e. UTIb and
high-density lipoprotein (HDL) and their antiviral
activities are presented in Table 1 [3,4,20]. ...

[...]

A broad antiviral activity may be an important
feature of an antiviral defence. Table 1 shows that
UTIb and HDL inhibited all of the viruses tested,
which included DNA and enveloped and nonenveloped
RNA viruses.

[...]

Human serum HDL is a lipoprotein of Mr 300 000
and occurs in the serum in the range of 30 to
80 mg/dL. Its antiviral property seems to reside in
its protein component apolipoprotein A-1. Apolipoprotein
A-1 has been reported to inhibit HIV
and HSV-1 [22,23]. As shown in Table 1 HDL is
broadly active against DNA and enveloped and
non-enveloped RNA viruses.

[...]

This early inhibition indicates that the antiviral action
of HDL occurred early in the virus growth cycle
and is consistent with an inhibition of viral
penetration as determined in the preceding
section.

This same type of experiment showed that HDL,
on the other hand, acts against most viruses at a
post-attachment stage. Further investigations of
mechanism of viral inhibition by HDL indicated
that HDL inhibits the multiplication cycle at an
early stage between 0 and 1 h of initiation, most
likely by preventing penetration of cell surface by
virus.

[...]

CONCLUSIONS
Innate antiviral substances present in human
plasma have not been carefully explored as
natural defences against viraemia and infection.
This review indicates that plasma contains several
naturally occurring nonspeci®c antiviral substances,
some of which are broadly active against
a wide range of DNA and enveloped and nonenveloped
RNA viruses. The mechanism of action
of the broadly active UTIb occurs during virus
attachment and that of HDL during virus penetration.
A limited study of the in vivo protective role
of some of the antiviral substances indicates their
importance against infection, particularly in early
stages of infection before reactive host defences,
like IFN and speci®c immunity, are induced.
Further studies are needed in this area of virology."

i'm using vit b5 too, to see what effect it has on cholesterol since from all research cholesterol is used by hbv, hcv, hiv.this vitamin is free of sides

in vitro evidence on hiv
Cystamine (pantethine) as a suppressor of HIV
AIDS Res Hum Retroviruses. 2009 Nov;25(11):1057-60
Sulfur metabolism in AIDS: cystamine as an anti-HIV agent.
Toohey JI.
Cytoregulation Research, Elgin, Ontario, Canada.
Numerous reports have documented disturbances of sulfur metabolism in
AIDS patients. There is a generalized loss of sulfur from the body,
measured as cysteine and glutathione. The enzyme, cystathionase, has
been shown to be greatly decreased in the liver of AIDS patients.
Cystathionase is known to catalyze beta elimination of cystine giving
rise to sulfane sulphur, which has potent stimulatory properties for
lymphocytes. When both cystine and cystathionase are deficient in AIDS,
the lymphocytes would lack this important regulator, which might be
replenished by giving cystamine. Cystamine is a small disulfide that
gives rise to sulfane sulfur when it undergoes oxidation catalyzed by
diamine oxidase (a ubiquitous enzyme in animals). Cystamine has been
shown to cause marked suppression of HIV replication in cultured
lymphocytes and macrophages; the inference is that the cystamine/diamine
oxidase system may replace the cystine/cystathionase system as a source
of sulfane sulfur. Sulfane sulfur could have two beneficial effects: (1)
it could increase the vigor and resistance of the lymphocytes and (2) it
could interfere with the HIV replication process. A clinical trial of
cystamine in AIDS is indicated.
PMID: 19886835

I just read your posts. I will put your questions to a Chinese researcher who knows about DHBV. I believe they already know the surface receptors on the duck's liver cells for the dhbv. I will see what he has to say.

I don't think this researcher will know much about cellular cholesterol - I don't know whether the term makes any sense.
"Cholesterol is a waxy steroid of fat that is manufactured in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals.[2] It is an essential structural component of mammalian cell membranes. It is required to establish proper membrane permeability and fluidity. In addition cholesterol is an important component for the manufacture of bile acids, steroid hormones, and Vitamin D."

like minerals, vitamins and so.....there are too type of content blood and cellular.of course we are interested in the cellular content because it is there that the virus uses cholesterol and not in the blood, lowering cholesterol in the blood is almost useless

so even lowering serum cholesterol to low levels the effect on virus might be very low/none, the good point is that liposomos dont stay in the blood but they enter cells directly and of course taking liposomes by mouth makes them enter fast in liver cells.liposomal gsh doens t lower serum cholesterol but cellular cholesterol first and then indrectly can lower the serum one

so the main point for me is, but i guess there is no response because all studies on this are still going on, how to make collesterol in the liver cells so low to interfere with hbv

the interference happens before cccdna/hbsag fromation and disturbs both entrance and exit too from the studies posted above

the patents indicates extremely high liposomal gsh doses, to be used hourly, but it would be too expensive to apply those doses

anyway i guess my hbsag in the following months can be the answer, this low cholesterol is indicated also for liver health/cirrhosis regression and to block firbosis development since we have found a study in the last months demostrating that cholesterol/sugars are implicated in the development of fibrosis and in its regression

anyway these are the results of cholesterol lowering by natural statins monacoli k (red yeast rice) 3mg daily and glutathione liposoms 9000mg daily which are reported in many studies as antiviral effect impairing hbsag secretion and infectivity of virions....

at the starting of the post i amde a mistake on liposomal glutathione quantity....it is not 9000mg but 900mg

March 9, 20110 Comments
Posted in News, Science & Research, Cholesterol, Immunity, Immune Health, Diet
Print
EDINBURGH, Scotland—Lowering cholesterol levels may boost the body’s ability to fight off viral infections, according to new a new study published in journal PLoS Biology.

Researchers at the University of Edinburgh discovered a direct link between the workings of the immune system and cholesterol levels. When the body succumbs to a viral infection, immune cells release the protein interferon, which sends signals to infected cells and causes cholesterol levels to be lowered. Cholesterol is needed for viruses and certain bacteria to grow; therefore, limiting the body's production of cholesterol would decrease the opportunity for viruses to thrive.

The researchers suggest the findings could lead to new ways of treating viral infections, targeting the cholesterol metabolism.

“What we have discovered is that a key immune hormone stimulated upon infection can lower cholesterol levels and thereby deprive viral infections of the sustenance they need to grow. Drugs currently exist to lower cholesterol levels, but the next step would be to see if such drugs would also work to help bolster our immune systems," said Professor Peter Ghazal, of the University's Division of Pathway Medicine.

A new study sheds some light on the interaction of the body's immune and metabolic systems suggesting that cholesterol may play a role in fighting off infections.

Researchers from the University of Edinburgh looked at the body's innate response to an infection to better understand how it is connected to cholesterol.

"What we have discovered is that a key immune hormone stimulated upon infection can lower cholesterol levels and thereby deprive viral infections of the sustenance they need to grow," Peter Ghazal, Chair of Molecular Genetics and Biomedicine at University of Edinburgh, said in a statement.

That key hormone is interferon, which lowered cholesterol in mice when they were infected with a range of different viruses.

The scientists, whose work appeared in the journal Public Library of Science (PLoS) Biology, do not think that the viruses need cholesterol itself to stay alive, but rather there is something else happening where the cholesterol is linked to protein production that viruses feed on.

Both the control mechanism of interferon and the gene activity of the cholesterol appear to be regulated by the same pathway.

Statin drugs, which are heavily prescribed to lower LDL, or "bad" cholesterol, have already been found to protect against some viruses in mouse models. Ghazal told Reuters that although there are already widely available cholesterol-lowering drugs, which are currently used to reduce the risk of stroke and heart attack, it would require years of research before his findings could be translated into clinical treatments for humans. He did however think that statins could be designed to have some anti-infective effects.

Today antiviral drugs target the ability of the virus to multiply, but researchers are looking for alternatives that would focus on the way the body responds to an infection rather than focusing on the intruder -- which has led to drug resistance in various bacteria and viruses.

Antiviral drug development is fundamentally more challenging than antibiotic development (e.g. against bacteria), due to rapid viral biochemical mutation that negates drug efficacy. It appears that directly attacking a virus will always be a struggle.

Consequently, it makes sense to think of fundamentally different approaches to antiviral treatment. Instead of directly attacking a virus, why not target a cellular biochemical system essential to viral infection and propagation?

Nicole Zitzmann (University of Oxford, United Kingdom) and coworkers have taken this approach to target hepatitis B, hepatitis C, and HIV infections. Their liposomes hindered viral propagation in infected cells, as well as viral infection of uninfected cells, by lowering cellular cholesterol levels.

Why target cholesterol biosynthesis?

Why would reducing cholesterol biosynthesis have any impact on a virus? Some viruses critically depend upon cholesterol and lipids for survival.

For example, HIV and hepatitis B and C utilize them for cellular entry, and hepatitis C and HIV require them for assembly within the cell. Despite this promise, clinical efforts at combating viral infections by inhibiting cholesterol have essentially failed, possibly due to cellular compensation for the cholesterol inhibition.

Future efforts may be more successful if cholesterol biosynthesis is targeted more effectively. This was the goal of Zitzmann and coworkers.

The indirect antiviral agent.

The scientists' weapon of war is the humble liposome, in this case microscopic spherical assemblies comprised of polyunsaturated lipids (multiple double bonds in the lipid chains). The liposomes can enter cells, and are targeted to the endoplasmic reticulum (a cellular subcompartment, important in protein synthesis and many other functions).

It's important to note that the liposomes do not contain drugs within them, in this research. Future research may utilize drugs in combination with the liposomes for enhanced antiviral activity.

Targeting cholesterol biosynthesis.

The scientists found that a liposome concentration of 50 micromolar (measured by the lipid content) was the highest utilizable concentration that was still essentially nontoxic to their cells. All further studies were carried out at this concentration.

Tested against lab-cultured liver and blood cells, cholesterol was reduced by somewhere between 33% and 54%, depending on the type of cholesterol and the specific type of cell. This demonstrates significant cholesterol inhibition regardless of the cell type.

It's possible that cholesterol inhibition was effected by activation of an enzyme (sphingomyelinase) critical to cholesterol removal from the cell membrane, in response to an influx of polyunsaturated lipids (i.e. the liposomes). The liposomes were superior to lovastatin (a drug used to control cholesterol levels), at nontoxic concentrations, in terms of cholesterol inhibition, which didn't significantly affect sphingomyelinase activity.

The scientists tweaked their liposomes with a synthetic polymer, poly(ethylene glycol), which is commonly used to improve liposome biocompatibility. Similar results were obtained, i.e. poly(ethylene glycol) is not needed.

Liposomes targeted to the general cell interior, as opposed to the endoplasmic reticulum, weren't effective. However, this isn't evidence that the endoplasmic reticulum is the only effective target for inhibiting intracellular cholesterol production.

Antiviral efficacy.

Now, on to the highlight of this research. The scientists' liposomes dramatically hindered viral activity.

Liposomes inhibited viral secretion by somewhere between 22% and 41%, depending on the virus and cell type. Viral infectivity was reduced by somewhere between 50% and 91%.

In contrast, treatment with lovastatin did not affect hepatitis C secretion from liver cells, and only reduced hepatitis infectivity by 48%. Clearly, the scientists' liposomes are more effective than levostatin at inhibiting the viruses, as expected due to lovastatins' inferior cholesterol targeting capacity.

Viral infectious levels were returned to normal by adding cholesterol to the cells. Viral spread is clearly closely related to intracellular cholesterol levels.

Pretreating noninfected cells with the liposomes reduced hepatitis C viral entry into cells by 94%, and that of HIV by 64% (the experiment could not be performed in the cells used for hepatitis B infection). Thus, not only do the liposomes hinder the spread of viruses from infected cells, they also hinder viral infection of healthy cells.

Further experiments demonstrated that hepatitis C infection was hindered by both reduced cholesterol in the cell membranes, as well as reduced expression (on the cell surface) of the protein CD81, important for viral attachment to the cell. No proteins important for HIV attachment to the cell were found to be altered by liposome treatment, but lipid rafts were less prevalent in the cell membrane.

Implications.

Zitzmann and coworkers have developed a novel and extraordinarily useful method of indirectly targeting viral infections, namely by inhibiting cholesterol biosynthesis. This approach is unlikely to be thwarted by viral adaptation, due to critical viral dependence upon cholesterol for cellular infection.

Furthermore, this approach can be readily adapted to include drugs within the liposomes, especially for targeting simultaneous viral infections which are less dependent upon intracellular cholesterol. Note that this advance is limited to viral infections which need cholesterol to infect and spread to other cells.

Nevertheless, HIV and hepatitis infections are a huge health burden, and taking them out is a worthy goal in itself. This research is complimentary to that aimed at cheaply synthesizing topical anti-HIV agents; perhaps such drugs can be used in combination with the liposomes described herein to dramatically improve the efficacy of standard HIV treatment.

NOTE: The scientists' research was funded by the Oxford Glycobiology Endowment, the Canadian Institutes of Health Research, United Therapeutics Corporation, and the Consiliului National al Cercetarii Stiintifice din Invatamantul Superior.

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